Tonneau covers are generally used to cover the bed of a vehicle, such as and without limitation, a pick-up truck. A typical tonneau cover includes two primary components: a cover sheet made of fabric or other flexible, preferably waterproof, material; and a frame to which the perimeter of the cover sheet is removably attached and which is usually adapted and employed to removably position the cover sheet or material over the bed of a vehicle, such as a pick-up truck. The frame generally comprises four rails: a left and right side rail, which are removably affixed to each respective and opposed sidewall of the pick-up bed, and a front and rear rail, which are respectively positioned near the passenger cab and the tailgate. Moreover, the front and rear rails are usually connected to each of the side rails by connecting or "corner" members which are generally manufactured from a material, such as, and without limitation, aluminum or plastic and which allow the rails to cooperatively and removably form a tonneau cover frame. The preferred method of manufacture of the rails is by extrusion of a durable, lightweight material, such as, and without limitation, aluminum.
The side rails are oftentimes rigidly attached to the side walls of the pick-up bed by clamps, bolts, or other adhesive means and generally extend along the upper rims of those walls, as shown and described in U.S. Pat. Nos. 4,639,033 and 5,058,652 of Wheatley, as well as in U.S. Pat. Nos. 4,730,866 and 4,838,602 of Nett, all of which are fully and completely incorporated herein by reference, word for word and paragraph for paragraph. In these prior connector assemblies, the front rail is rigidly attached to the front wall of the pick-up bed by similar means or removably attached to the side rails by these connecting or "corner" members. The rear rail is similarly and removably attached to the side rails by these connecting or "corner" members.
In most of these prior tonneau cover assemblies, the cover sheet generally remains attached to the front rail, and is adapted to be moveable from a first "rolled up" or non-operative position in which the cover is secured to the front rail by straps, to a second fully extended and operable position in which it covers all of the rails and protects the truck or vehicle bed. The front of the cover sheet is generally attached to the front rail using a cylindrical dowel member which is sewn into the cover fabric or by means of an extruded member, a portion of which is generally cylindrical or generally semi-cylindrical in shape, and which is also sewn into the cover fabric. The dowel or extruded member is generally manufactured from a flexible material such as, but not limited to plastic. The outer edge of the front rail has a circular, concave bight which extends the entire length of the rail. The dowel (or portion of the extruded member) is made to be approximately as long as the front rail and to have a diameter slightly smaller than the bight so that it may easily slide into the rail from one end but remain frictionally engaged in the front rail bight. Once the dowel (or portion of the extruded member) is slid into the rail, the corner members may be attached to both ends of the front rail in a manner which allows the front rail to be connected to the side rails.
Various assemblies have been used to operatively connect these various rails to form or create a tonneau frame. Most assemblies employ corner members which have a somewhat triangular configuration, as described in U.S. Pat. No. 5,121,960 of Wheatley, which is herein incorporated by reference, word for word and paragraph for paragraph. In one type of prior connector assembly, each of the corner members has a pair of plugs which are orthogonally positioned or disposed at a right angle with respect to each other and which are received by the hollow ends of the rails. When the perimeter of the sheet is attached to the rails, the corner members and the front and rear rails are held in place through fabric tension created by the sheet. The plugs may also have flexible barbs which fill the hollow ends of the rails, thereby creating a frictional force which aids in holding the corner members and rails in place. One drawback associated with this first type of prior connector assembly is that the tension created by the extended sheet is used to hold the rails in place. Thus, when a truck is being driven, or otherwise utilized, without the cover sheet extended to its operable position and attached to hold the rails in place, the corner members and rails will often loosen due to the vibration of the vehicle. Such vibration can cause disturbing audible noise or even result in the detachment and loss of corner members and/or rails.
Another type of prior connector assembly utilizes and includes a plurality of holes which are bored into the sides of the rails and which correspond to substantially similarly sized holes which reside in the plugs of the corner members. The plugs are received by the hollow ends of the rails and pins or plastic rods are inserted into the holes and lock the corner members and rails together. This assembly generally provides more security than the previously described connector assembly. However, a significant amount of time is required to connect and disconnect the rails and corner members since the holes must be aligned before the pins or rods are inserted. Furthermore, the pins and rods may loosen due to vibration causing disturbing vibratory noise and/or the detaching and loss of corner members and/or rails.
Yet another prior assembly utilizes and includes screw fasteners which secure the plugs into the rails. One such assembly is described in U.S. Pat. No. 5,251,951 of Wheatley, which is herein incorporated by reference, word for word and paragraph for paragraph. While more secure than the previously described assemblies, this connector assembly requires the costly threading of its various parts. Furthermore, the assembling and disassembling of the tonneau frame requires an operator to respectively fasten and unfasten a multitude of screws, resulting in a substantial investment of time. Moreover, the screws utilized in this assembly can also loosen with extended usage, resulting in an unstable frame and the potential detachment and loss of corner members, rails and screws.
Perhaps the most secure, cost effective and convenient connector assembly to date has utilized plastic clips which are formed as an integral part of each corner member. In this assembly, each corner member comprises a substantially "one piece" assembly with two plastic clips, each clip corresponding to one of the two plugs of the corner member. The plastic clips each have a "button" or detent which must be manually depressed by a user while the plug is simultaneously inserted into the hollow rail end. To remove each corner member, the button or detent is manually depressed while the corner is pulled away from the rail to which it is attached. A first drawback associated with this assembly is that both the insertion and the removal of the corner members require two separate actions which must occur simultaneously. That is, the detent must be depressed at the same time that the plug is inserted or removed from the rail. This makes connecting and disconnecting the tonneau frame more time consuming and difficult than it would otherwise be with a one-step procedure. A second drawback is that the plastic clip engages the rail at substantially the same moment as the plug, making the assembly procedure "clumsy" and inconsistent. This condition also demands substantial time and concentration from the user or installer, and if insertion is made at an improper angle, the plastic clip may become deformed or break.
All of the aforementioned prior connector assemblies suffer from yet another drawback. That is, in all of the aforementioned prior assemblies, in order to attach or remove the tonneau cover sheet, an operator must first disconnect the front rail and remove the attached corner members. This is necessary because the cylindrical bight cannot be exposed until the corner member(s) is removed. This process is cumbersome, time consuming and requires that the front rail be positioned (or located) at some distance away from the front of the pick-up cab so that it may be removed without removal of the side rails.
There is therefore a need to provide a connector assembly which allows for the relatively easy formation of a tonneau frame and which overcomes some or all of the difficulties and drawbacks of the various previously delineated prior art designs; which is relatively inexpensive to manufacture; and which uses a corner member having a plastic clip and a plug and which is adapted to allow the plug to be inserted into a hollow rail end before the clip engages the rail, thereby ensuring a smooth, consistent assembly; which minimizes the time and difficulty required to connect and disconnect the corner members and rails; and which allows the tonneau cover sheet to be attached to and removed from the front rail without requiring removal of the front rail and/or corner members attached to the front rail.